Fuel leak prevention system

ABSTRACT

A fuel leak prevention system and method for providing same includes a check valve for insertion into the discharge end of a spout assembly of a fuel dispensing nozzle, the check valve being located downstream of the nozzle&#39;s fuel control valve so as to prevent any leaking or dripping of fuel from the spout when the nozzle is deactivated. The check valve includes a pivoting flap that is preferably spring-loaded and predisposed to remain closed to seal the spout when there is no fuel flowing through the nozzle, but which is allowed to rotate within the spout to open the nozzle and allow the flow of fuel when the nozzle is activated. In one embodiment, the check valve can be inserted into the spout during fabrication of the nozzle. An alternate embodiment allows the retrofit of an existing nozzle by adding an extension that contains the check valve to the spout on the nozzle. The system and method disclosed has application to any liquids that are to be dispensed, including petrol, diesel, kerosene, gas oil, gas, liquid petroleum gas, av-gas, chemicals, and water.

CROSS-REFERENCE TO RELATED APPLICATION AND PRIORITY CLAIM

This application is a continuation in part of U.S. Non-Provisionalpatent application Ser. No. 12/580,678, filed 16 Oct. 2009, whichapplication claims the benefit of U.S. Provisional Patent ApplicationSer. No. 61/106,195, filed 17 Oct. 2008. Each of the above-listedapplications is herein incorporated by reference as if fully set forthbelow in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention relate generally to a fuel leakprevention system, and more particularly to a system to prevent fuelfrom leaking or dripping from the dispensing end of a fuel nozzle afterthe nozzle has been deactivated.

2. Description of Related Art

Fuel dispensing nozzles of the general type used on fuel pumps infueling stations are well understood in the art. These nozzles arenormally provided with hold-open catches for holding an operating leverin an open position, and are provided with an automatic shut-off meansfor shutting off the flow of fuel from the nozzle when the tank levelreaches the discharge end of the nozzle. The hold-open catch feature andthe automatic shut-off means allow the operator to leave the nozzleunattended during the filling operation without fear that the tank willoverflow should it become full while the nozzle is unattended.

The fuel nozzle generally works off of pressure created by the flow offuel from the pump. When the hold-open latch is engaged, the poppetvalve stem is open, allowing fuel to flow. As the fuel flows, theanti-drain valve in the spout is open, which sucks air into a vacuumchamber above the poppet valve.

As long as the vacuum chamber is in equilibrium with the atmosphericpressure beneath the diaphragm of the chamber, the poppet is engaged,and the flow of fuel will continue. When either the hold-open latch isdisengaged, or when the anti-drain valve is covered by fuel (full tank)air intake ceases, and the poppet valve stem closes, disrupting the flowof fuel.

Since the point of closure is in the handle of the nozzle, there is anarea between the poppet and the end of the spout where fuel may remainafter fueling. Depending on the length, the diameter, and the curvatureof the spout, the fuel retained in this area can vary from a few dropsto several ounces. Thus, fueling nozzles retain fluid between theshut-off mechanism and the end of the spout.

This uncontained fuel can be spilled on the car, ground, or on the body,creating a fire, clean-up, and environmental hazard. In such a nozzle,it is sometimes desirable to provide for a shut-off valve at the tip ofthe nozzle spout and in the fuel supply passage to avoid drips from thespout after the nozzle is removed from the fill tube of a fuel tank ofthe motor vehicle, as there is ever increasing concern about damage tothe environment resulting from the contamination of ground water andsoil due to spillage of vehicle fuels, petroleum substances and otherchemicals. Part of the damage is caused by the dripping of excess liquidfrom the nozzle used to dispense the fuel or liquid, after the nozzlehas been deactivated. As described, in general, once the nozzle isdeactivated, there remains a small amount of excess liquid in thenozzle. As the nozzle is removed from the fuel tank or container, theremaining liquid tends to drip from the dispensing end of the nozzleonto the surrounding ground surface or onto the user. In addition, partof the damage is caused by activation of the nozzle when the nozzle isremoved from the container or fuel tank. Activation of a nozzle outsideof a container or fuel tank also presents a safety problem due to thespillage of the flammable fuel.

Fueling stations rely on consumers to dispense fuel. A typical nozzle ishandled hundreds of times a day. Spillage from the spout is normal. Thewasted fuel may eventually enter a storm drain through run off andcleaning procedures. Fuel seeping into the ground contaminates soil,streams, rivers, lakes, and drinking water. For example, one quart ofspilled fuel can contaminate 250,000 gallons of fresh drinking water.One pint of fuel seeping into a lake can create a one acre slick,preventing the replenishment of oxygen, blocking sunlight, and impairingphotosynthetic processes.

Spilled fuel also releases Volatile Organic Compounds (VOC's) that havelong and short term adverse health effects. VOC's are organic chemicalcompounds that have high enough vapor pressure under normal conditionsto significantly vaporize and enter the atmosphere. These vaporscontribute to air pollution and greenhouse gases.

The cost of fuel is also a consideration to retain spillage. At US$4.00per gallon, one ounce of fuel costs US$0.03. Over many spills, this canamount to a large amount of fuel inventory lost. There is also, ofcourse, the considerable inconvenience and potential safety hazards thisproblem poses to the consumer, including the risk of spillage ordrippage onto clothes, shoes, or hands, not to mention the safetyhazards posed by drippage of fuel onto the driveways at fuelingstations.

To help prevent spillage of the liquid, a non-drip assembly is needed toprevent the excess liquid from dripping from the end of the nozzle oncethe nozzle has been deactivated. The related art has shown variousapparatus for preventing a liquid dispensing nozzle from dripping liquidafter the nozzle has been deactivated. Illustrative are U.S. Pat. No.4,014,472 to Bennett; U.S. Pat. No. 4,213,488 to Pyle; and U.S. Pat. No.5,377,729 to Reep.

Bennett describes a nozzle assembly for high speed filling units. Thenozzle assembly includes an upper casing within which is mounted anozzle piston structure. The piston structure is fastened to an inner,hollow sleeve member to move the sleeve member. The sleeve member isprovided with openings adjacent the piston structure to allow forcommunication between the inner space of the hollow sleeve member andthe cylinder space. The end of the inner sleeve member opposite thepiston structure is provided with discharge openings and a plug-like endclosure member. A spring mounted around the inner sleeve member acts tobias the sleeve into the closed position. An outer sleeve member isslidably mounted around the inner sleeve member and is fixably securedto the lower casing of the nozzle assembly. In operation, the pressureof the fluid causes the piston to open which in turn moves the innersleeve member outward thus, moving the end of the inner sleeve memberbeyond the outer sleeve member which exposes the discharge openings.Once the flow of fluid stops, the spring biases the piston structure andthe inner sleeve member into the closed position.

Pyle describes a valve located in the end of a nozzle for preventing theflow of fuel and fuel vapors out of the nozzle when the nozzle isdeactivated. In one embodiment, a pinch valve is located at the end ofthe nozzle. The pinch valve comprises a resilient sleeve and is designedto open and close by the action of air or hydraulic pressure acting onthe resilient sleeve. A fluid passageway is provided to establishcommunication between the pinch valve and the flow passage upstream ofthe flow control valve. When the nozzle is deactivated, the pinch valveis in fluid contact with the flow passage such that the pressure fromthe fluid flowing to the pinch valve acts to close the pinch valve. Whenthe nozzle is activated, a passageway is formed between the fluidpassageway and the flow passage downstream of the flow control valvesuch that the fluid flows out of the fluid passage and the pinch valveand out of the flow passage. In another embodiment, a wafer valve ismounted in the end of the nozzle and acts to seal the end of the nozzle.The wafer valve comprises two substantially semi-circular discspivotally arranged around a shaft which extends from one side of the endof the nozzle to the other to support the discs. The wafer valve uses asimilar construction as described above to open and close.

Reep describes a check valve device for a fuel pump nozzle. The deviceincludes a stopper having a stem mounted on a plug member. The plugmember is sized to close the dispensing end of the nozzle. A supportmember is mounted on the stem of the stopper to guide and support thestopper. The support member has two extension members mounted in anessentially U-shaped manner. The extensions engage the inside wall ofthe nozzle to hold the support member securely within the passage. Thesupport member is shaped to allow the fuel to pass through the nozzle. Aspring is mounted between the end of the stem opposite the plug memberand the support member. The spring acts to bias the stopper back intoengagement with the end of the nozzle. In operation, the plug member isseated within the end of the nozzle when fuel is not being dispensed.Once the fuel pump is activated, the fuel pressure on the plug memberacts to move the plug member out of engagement with the end of thenozzle. Once the pump is deactivated, the force acting to disengage theplug member is less than the force of the spring acting to move the plugmember back into engagement with the end of the nozzle. Consequently,the plug member acts to close the end of the nozzle such as to preventthe nozzle from dripping.

Also of some interest are U.S. Pat. No. 3,324,904 to Crotners; U.S. Pat.No. 4,749,010 to Petell; and U.S. Pat. No. 4,834,151; and U.S. Pat. No.5,249,611 all to Law which show non-drip apparatus which are activatedby removal of the nozzle from contact with the container.

Further, of interest are U.S. Pat. No. 2,936,799 to Mannon; U.S. Pat.No. 3,521,679 to Copony; U.S. Pat. No. 3,994,323 to Takahata et al. andU.S. Pat. No. 5,076,333 to Law which show the closing off of the venturiopening or the air vent tube in response to removal of the nozzle fromthe container or fuel tank which stops the flow of liquid in the nozzle.

There remains a need for a liquid dispensing nozzle that will not dripexcess liquid once the nozzle is deactivated. What is needed is a systemof isolating any remaining liquid between the poppet stem valve and theterminal end of the spout, in order to retain any remaining liquid inthe nozzle, and eliminate leakage. It is to such a system that thepresent invention is primarily directed.

BRIEF SUMMARY OF EXEMPLARY EMBODIMENTS OF THE INVENTION

Briefly described, in preferred form, the present invention is a fuelleak prevention system that comprises a check valve insert comprising apivoting flap that is preferably spring-loaded and located in proximityto the dispensing end of the spout of a fuel dispensing nozzle. Thecheck valve insert prevents the flow of fuel at the terminal end of thespout. By stopping the flow of fuel in proximity to terminal end of thenozzle (as opposed to at a location interior to the nozzle, e.g., thepoppet valve stem in the handle of the nozzle), there is no drippage ofthe fuel that remains in the spout after the nozzle has beendeactivated. The check valve insert is positionable in proximity to theoutlet end of the fuel dispensing nozzle. In one embodiment, the checkvalve can be inserted into the spout during fabrication of the nozzle.An alternate embodiment allows the retrofit of an existing nozzle byadding an extension that contains the check valve to the spout on thenozzle.

A fuel dispensing nozzle of the present invention generally includes aninlet for the fuel being pumped, a spout for dispensing of the fuel, apoppet valve between the inlet and outlet, and a handle that is operableto move the poppet valve between an opened position in which fuel canflow from the inlet to the spout and a closed position in which fuel isprevented from flowing from the inlet to the spout. The presentinvention also has application to any liquids that are to be dispensed,including petrol, diesel, kerosene, gas oil, gas, liquid petroleum gas,av-gas, chemicals, and water.

An isolation system is herein disclosed to isolate remaining fuelbetween the poppet stem valve and the terminal end of the spout by meansof a flapper valve. The flapper valve is activated (opened) by thepressure created by the flow of fuel from the pump. When the flow stops,the valve closes, since the resistant pressure is not enough to maintainthe valve in the open position. Consequently, remaining fuel in thenozzle is retained in the spout.

In an exemplary embodiment, the present invention is a leak preventionsystem for use with a liquid dispensing nozzle, the nozzle in fluidcommunication with a liquid dispensing pump, the system comprising abody portion, a spout assembly extending from the body portion, thespout assembly having an outlet end configured for dispensing theliquid, a flow control valve in the body portion operable to allow orprevent the flow of liquid through a flow passage defined by the bodyportion, and a check valve positioned within the spout and downstream ofthe flow control valve and being responsive to the flow of liquidthrough the body portion and into the spout assembly, wherein the checkvalve is biasedly disposed to remain closed when no liquid is flowingthrough the nozzle so as to prevent liquid from dripping from the outletend when the nozzle is not activated. The check valve can be located inproximity to the outlet end of the spout. The check valve can comprise aflap member (also referred to as a “flapper valve”) being pivotablyattached within the spout, and a closing member mounted within the spoutand oriented to engage the flap member to apply a closing force to theflap member, wherein the force applied by the closing member is largeenough to cause one face of the flap member to seat in the spout (tolimit if not prevent the flow of liquid) and to remain seated when thenozzle is not activated, but the force is not so large to prevent theflap member from rotating to substantially open the spout and allow theflow of liquid when the nozzle is activated. The closing member can be aspring or any other mechanical device that can apply a closing force tothe flap member (e.g., piston, actuator, elastic member).

The present leak prevention system can further comprise a stop memberpositioned inside the spout and adapted to provide a seating area forthe face of the flap member to be seated and for preventing the flapmember from rotating beyond a preset orientation. The present system canfurther comprise a hinge pin secured inside the outer end of the spout,wherein the flap member further comprises a tab located at an outer edgeof the flap member, the tab having a bore through a longitudinal axis ofthe tab and configured to receive the hinge pin such that the flapmember can rotate about the longitudinal axis. In an exemplaryembodiment, the closing member is a rotational spring configured toreceive the hinge pin such that the spring member is in constantcommunication with the flap member and such that the spring member canapply a closing force to the flap member when it is desired to shut offthe flow of liquid through the spout. In such an embodiment, the hingepin can be fixedly attached to an inner wall of the spout, wherein theinner wall contains a groove adapted to receive an upper surface of thetab and at least a portion of the spring member such that the axis ofrotation of the flap member is partially located within the inner wallto allow the flap member to rotate within the spout and fully seatagainst the stop member without interference from the inner wall. Theclosing member can also be a linear spring, configured to be fixedlysecured inside the outer end of the spout at one end and rotatablysecured to the flap member at an opposing end, such that the spring canapply a closing force to the flap member when it is desired to shut offthe flow of liquid through the spout.

The flap member of the system can be constructed, for example, of metalor an elastomeric material. One or both faces of the flap member canfurther comprise a reinforced portion centrally located and configuredto receive the closing member so as to effectively distribute the forceto be applied by the closing member across the flap member. Thus, in anembodiment where the closing member preferably a rotational springmember, the reinforced portion of the flap member comprises a raisedface sized to accept the force-producing portion of the rotationalspring member as it pushes against the flap member. Similarly, in anembodiment where the closing member comprises a linear spring member,the reinforced portion of the flap member preferably comprises a raisedface sized to accept the rotatably-secured end of the linear springmember as it pulls the flap member into the closed (fuel-off) position.

In another exemplary embodiment, the present invention can be a methodfor preventing leakage from an outlet end of a liquid dispensing nozzle,comprising providing a nozzle in fluid communication with a liquiddispensing pump, the nozzle including a body portion, a spout assemblyextending from the body portion, and a flow control valve in the bodyportion operable to allow or prevent the flow of liquid through a flowpassage defined by the body portion, wherein the spout assembly has anoutlet end configured for dispensing the liquid, and providing a checkvalve positioned in the outer end of the spout and being responsive tothe flow of liquid through the body portion and into the spout and beingbiasedly disposed to remain closed when no liquid is flowing through thenozzle so as to prevent liquid from dripping when the nozzle is notactivated, the check valve comprising a flap member being pivotablyattached within the outer end of the spout, and a closing member,preferably a spring, mounted within the outer end of the spout andoriented to engage the flap member by applying a closing force to theflap member sufficient to seat the flap member when the nozzle is notactivated, and to allow the flap member to rotate to substantially openthe spout and allow the flow of liquid when the nozzle is activated.

These and other objects, features and advantages of the embodiments ofthe present invention will become more apparent upon reading thefollowing specification in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a perspective view of a conventional fuel dispensingnozzle that can be adapted to incorporate a fuel leak prevention systemin accordance with an embodiment of the present invention.

FIGS. 2A and 2B illustrate side and cross-sectional views, respectively,of a conventional fuel dispensing nozzle that can be adapted toincorporate a fuel leak prevention system in accordance with anembodiment of the present invention.

FIG. 3A illustrates an enlarged view of the area of the portion I-I ofFIG. 2A.

FIG. 3B illustrates an enlarged view of the area of the portion II-II ofFIG. 2B.

FIG. 4A illustrates a perspective view of an assembled configuration ofa check valve insert inside a spout assembly in accordance with oneembodiment of the present invention employing a rotational springmember.

FIG. 4B illustrates a perspective cross-sectional view of the assembledconfiguration of FIG. 4A.

FIG. 4C illustrates a perspective cross-sectional view of an assembledconfiguration of a check valve insert inside a spout assembly inaccordance with an embodiment of the present invention employing alinear spring member.

FIG. 5A illustrates a perspective view of a flapper valve to be used inconjunction with a rotational spring member and depicting the insertionof a hinge pin in accordance with one embodiment of the presentinvention.

FIG. 5B illustrates a cross-sectional view of the flapper valve of FIG.5A as seen along the section III-III of FIG. 5C in accordance with oneembodiment of the present invention.

FIGS. 5C and 5D illustrate front and side views of the flapper valve ofFIGS. 5A and 5B in accordance with one embodiment of the presentinvention.

FIG. 5E illustrates a perspective view of a flapper valve to be used inconjunction with a linear spring member in accordance with oneembodiment of the present invention.

FIG. 6A illustrates a perspective view of a rotational spring member anddepicting the insertion of a hinge pin in accordance with one embodimentof the present invention.

FIG. 6B illustrates side and front views of the rotational spring memberof FIG. 6A, shown in both the nominal (closed) and fully open positionsin accordance with one embodiment of the present invention.

FIG. 7 illustrates a side view of a spout extension for attachment to aspout of a fuel dispensing nozzle in accordance with an alternateembodiment of the present invention.

The detailed description explains the exemplary embodiments of theinvention, together with advantages and features, by way of example withreference to the drawings.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now in detail to the drawings, wherein like reference numeralsrepresent like parts throughout the several views, FIG. 1 illustrates aperspective view of a conventional fuel dispensing nozzle (“nozzle”) 100that can be adapted to accept a fuel leak prevention system 1000 (FIGS.3B, 4-7) in accordance with an exemplary embodiment of the presentinvention. The nozzle 100 is well understood in the art, and will begenerally described in more detail below.

Reference here is made to a fuel dispensing nozzle most commonlyassociated with a “fueling station” at which customers pump liquid fuelinto their vehicles or into a storage container. For convenience, theterm “fuel” (F) is used herein to describe the material to be dispensedvia the nozzle 100. It is contemplated, however, that the nozzle 100 iscapable of delivering liquid of any sort, for example petrol, gas oil,kerosene, diesel, liquid petroleum gas (LPG), gas, av-gas, chemicals,and water. As shown, the system of the present invention is designed toprevent fuel from leaking or dripping from the dispensing end of thenozzle after the nozzle has been deactivated.

There are likely thousands, if not millions of such fueling stations inthe United States and worldwide, each of which already incorporatesmultiple nozzles of the sort described here. Thus, for example, in atypical fueling station (e.g., convenience store) there may be anywherefrom four (4) to eight (8) individual dispensing pumps, each containingat least one (1) nozzle for the most commonly dispensed fuels (regularunleaded, mid-grade unleaded, premium unleaded, diesel). As new fillingstations are constructed, or as filling station owners replace nozzlesat existing filling stations, it is desirable to provide a fuel leakprevention system that can be incorporated directly into the manufactureof the nozzle. It is to such a need that a preferred embodiment of thepresent is directed. On the other hand, to the extent that the nozzlesare already in place at existing filling stations, what is desired is afuel leak prevention system that can be adapted to upgrade or refurbishan existing nozzle, so that the advantages of the present invention canbe realized without necessitating the expense of replacing the entirenozzle. Thus, an alternate embodiment of the present invention isdirected to fill this need.

Nozzle

The operation of a conventional nozzle 100 will now be explained byreference to FIGS. 1, 2A, 2B. The nozzle 100 generally comprises a body120, which is in fluid communication with a fuel dispensing pump (notshown) that supplies fuel F into the body 120 via a hose 140; a mainvalve 160 positioned within the body 120 that provides control over theflow of fuel F through the body 120; a spout assembly 300 that issecured to the body 120 and is shaped to engage the mouth of a container(not shown) into which the nozzle 100 transfers fuel F; latch means 210for selectively closing and prohibiting the opening of the main valve160; and automatic shut-off means 400 for closing the main valve 160when the fuel F reaches the discharge end 320 of the spout assembly 300.

Body

The body 120 defines an internal passageway through which the fuel F isdispensed from its source (as depicted here, the hose 140) into thespout assembly 300 (described below) and finally deposited into themouth of a vehicle's fuel tank or a storage container (not shown). Thepassageway of the body 120 is provided with an inlet port 130, theexterior surface of which is typically shaped as a cylindrical body forease of hand holding, and which is releasably connected in fluidcommunication to the dispensing pump, and an outlet port 150, which isconnected to the inlet port 310 of the spout assembly 300.

The body 120 is further provided with a cap member 410 that isreleasably mounted on the body 120, whereby the cap member 410 and thebody 120 define an automatic shut-off chamber 480 that is incommunication with and functions as part of the automatic shut-off means400 (described below).

The body 120 further comprises a handle portion 220, which is adaptedfor attachment to the cylindrical exterior surface portion of the inletport 130 to form a convenient handhold for the customer, and whichencloses the operating lever 200 (described below) that the customeruses to control the operation of the nozzle 100.

The handle portion 220 may also optionally be fitted to accommodate ahold-open clip 240 that works in conjunction with the automatic shut-offmeans 400 (described below) to allow the operator to leave the nozzle100 unattended during the filling operation without fear that the tankwill overflow should it become full while the nozzle 100 is unattended.To accomplish this feature, the upper surface of the lower extremity ofthe handle portion 220 may optionally be fitted with a series of raisedridges or grooves (cut outs) 230 so as to accept the optional hold-openclip 240 that is pivotably attached to the operating lever 200.

Main Valve

The main valve 160 comprises a valve seat 430 adapted to be incommunication with the latch means 210 (described below) through a valvestem 440 that is fixedly secured to the attached operating lever 200.The main valve 160 is mounted within the body 120 between the inlet port130 and the outlet port 150 for selectively opening and closing thepassageway to allow control of the flow of the fuel F from the hose 140into the spout assembly 300. The main valve 160 is normally biased to aclosed position such that the flow of fuel F is prevented from flowingunless and until the customer engages the latch means 210 (describedbelow) by pressing the attached operating lever 200 to selectively openthe main valve 160 to allow the flow of the fuel F through the body 120.

Spout Assembly

The spout assembly 300 is comprised of a spout 340, which includes aninlet section 310 secured to the outlet port 150 of the body 120, and anoutlet section 320 opposite the inlet section 310 for dispensing andselectively directing the flow of the fuel F from the nozzle 100. Thespout assembly 300 is configured to engage the mouth of a vehicle's fueltank or a storage container (not shown) into which the nozzle 100transfers fuel F.

The spout 340 may optionally include coils 330 secured to itscircumference in the manner shown as in FIG. 2A to help maintain thespout 340 in the fill tube of a vehicle particularly during unattendedfueling as described earlier.

Latch Means

The latch means 210 comprises an operating lever 200, which may includethe optional hold-open clip 240 as described above, the lever 200 beingin communication with the main valve 160 through the attached valve stem440 as described above for selectively closing and prohibiting theopening of the main valve 160 to allow control of the flow of fuel F.The latch means 210 is further pivotably attached to a plunger 450 foroperation of the vacuum diaphragm 460 in connection with the automaticshut-off means 400 (described below) to allow closing the main valve 160when the fuel F reaches the discharge end 320 of the spout assembly 300.

Automatic Shut-Off Means

The automatic shut-off means 400 generally comprises a vacuum diaphragm460 mounted between the cap member 410 and the body 120 transverselydividing the automatic shut-off chamber 480 so as to define a vacuumchamber 420 as depicted in FIG. 2B. The vacuum diaphragm 460 is securedto the latch means 210 by way of a plunger 450 such that preselectedmovement of the plunger 450 releases the latch means 210 so as to closeand prohibit the opening of the main valve 160.

The automatic shut-off means 400 further comprises a poppet valve 500,which is provided with a poppet valve stem 510 that opens or closes apoppet valve seat 520 for generating a venturi effect in a well knownmanner; a vacuum conduit 530 for connecting in fluid communication thevacuum chamber 420 with the poppet valve seat 520; and an anti-drainvalve assembly 600 for connecting in fluid communication the vacuumchamber 420 with the discharge end 320 of the spout assembly 300.

The anti-drain valve assembly 600 comprises a vent tube 360 forconnecting in fluid communication the vacuum chamber 420 with thedischarge end 320 of the spout assembly 300 through the vent opening 350located at the terminal end of the vent tube 360 as depicted in FIGS.2B, 3B.

As described here, the nozzle 100 generally works off of pressurecreated by the flow of fuel F from the dispensing pump (not shown). Whenthe operating lever 220 is engaged, the poppet valve stem 510 is open,allowing fuel F to freely flow. As the fuel F flows into a fuel tank ofa vehicle or a container that is not full, the vent opening 350 of theanti-drain valve assembly 600 is unobstructed (open), which allows airto be sucked into the vacuum chamber 420 located above the poppet valve500.

As long as the vacuum chamber 420 is in equilibrium with the atmosphericpressure beneath the diaphragm 460, the poppet valve 500 is engaged(open), and the flow of fuel F will continue. When the operating lever200 is disengaged or when the vent opening 350 of the anti-drain valveassembly 600 is covered by fuel F (signifying a level of the fuel tankor container is full, which, in turn, releases the hold-open clip 240 asdescribed above), air intake into the vent tube 360 ceases, the poppetvalve stem 510 causes the poppet valve seat 520 to close, disrupting theflow of fuel F.

Operation of the Nozzle

During operation of the nozzle 100, the customer grabs the handhold(formed by the inlet port 130 and the handle guard 220) and presses theoperating lever 200 of the main valve 160, which causes the main valve160 to open and allows fuel F to pass through the passageway of the body120 in the direction of the poppet valve 500. As seen in FIG. 2B, thepoppet valve 500 is biased in a closed position by a spring or othercompression means (not shown) such that fuel F is prevented from flowinginto the spout assembly 300. As the fuel F flows through the body 120,the force of the pressure from the fuel is sufficient to overcome thecompression means such that the poppet valve 500 moves in the directionof the outlet port 150, allowing fuel F to flow freely though the body120, through the spout assembly 300, and into the fuel tank or container(not shown). Fuel F will continue to flow in this manner provided theoperating lever 200 is still pressed (the customer may or may not haveengaged the hold open clip 240 to allow unattended fueling) until suchtime as the vent opening 350 of the vent tube 360 becomes blocked,signifying the fuel level has nearly reached the top of the vehicle'sfuel neck or the container. Upon reaching this condition, the automaticshut-off means 400 is activated to close the main valve 160 therebydeactivating the nozzle 100 and preventing any further fuel F fromflowing to the spout 340.

Since the point of closure of the main valve 160 in a conventionalnozzle is located within the body 120 of the nozzle 100, there is anarea between the poppet valve 500 and the dispensing end 320 of thespout 340 where fuel F may remain after fueling (once the nozzle 100 hasbeen deactivated). Depending on the length, the diameter, and thecurvature of the spout 340, the fuel F retained in this area can varyfrom a few drops to several ounces. Thus, it is desirable to prevent anyof this residual fuel F remaining in the body 120 and the spout 340 fromdripping or leaking out of the dispensing end of the spout 320. It is tothis problem that the fuel leak prevention system 1000 of the presentinvention is directed.

As described thus far, the nozzle 100 is conventional and isrepresentative of nozzles of the sort used at most fueling stations.However, as mentioned, the disclosed invention has application toapplication to any liquids that are to be dispensed, including petrol,diesel, kerosene, gas oil, gas, liquid petroleum gas, av-gas, chemicals,and water.

Fuel Leak Prevention System, First Exemplary Embodiment

In a first exemplary embodiment of the fuel leak prevention system 1000of the present invention, the nozzle 100 is also conventional andoperates as described thus far. An embodiment of the assembled system isdepicted in FIGS. 4A, 4B. This embodiment of the fuel leak preventionsystem 1000 incorporates a check valve insert that comprises a flappervalve 700, a closing member, preferably a spring 800, and a hinge pin900 combined to function as a spring-loaded pivoting flap, which can bepreferably inserted into the dispensing end 320 of the spout 340 of afuel dispensing nozzle 100 and thus is generally circular shaped so asto fit within the inner diameter of the spout 340 (FIG. 4A). In thisembodiment, the closing member is depicted as a rotational spring member800, which rotates about the longitudinal axis of the hinge pin 900 andis configured to be in constant communication with the flapper valve 700to apply a closing force to the flapper valve 700 when it is desirableto shut off the flow of liquid through the spout 340. In the embodimentdepicted in FIG. 4C, the closing member is depicted to comprise a linearspring member 800, which is fixedly secured inside the spout 340 at oneend 830 of the spring member 800 and rotatably secured to the flapmember 700 at an opposing end 820 of the spring member 800, to apply aclosing force to the flapper valve 700 when it is desired to shut offthe flow of liquid through the spout 340. The check valve insertprevents the flow of fuel F at the terminal end 320 of the spout 340. Bystopping the flow of fuel F at that location (as opposed to at alocation interior to the nozzle 100, e.g., the poppet valve stem 510 inthe body 120 of the nozzle 100), there is no drippage of the fuel F thatremains in the spout 340 after the nozzle 100 has been deactivated. Thecheck valve insert is positionable in proximity to the dispensing end320 of the spout 340, and it can be located below the vent opening 350so as to not interfere with the function of the automatic shut-off means400.

Flapper

An embodiment of the flapper valve 700 (FIG. 5A) is shaped as a circularplate so that its diameter is less than the inner diameter of the spout340 but greater than a graduated stepped down area 720 at the end 320 ofthe spout 340. The stepped down area 720 is necessarily smaller indiameter than the diameter of the flapper valve 700 such that theflapper valve 700 presses flat against the radial portion of the steppeddown area 720 in order to form an effective seal to prevent fuel F fromleaking from the end 320 of the spout 340. In an embodiment where theclosing member comprises a rotational spring 800, the flapper valve 700is substantially flat on one surface 730 (FIGS. 5A, 5B, 5D), the sealingsurface, while the opposing surface contains a reinforced circularportion 740 (FIGS. 5A, 5B, 5C) that provides a stiffened localized areafor the rotational spring member 800 (described later) to press againstso as to apply the closing force to the flapper valve 700. Thereinforced circular portion 740 is not necessary to the presentinvention, but can provide enhanced performance for the reason juststated. In an embodiment where the closing member comprises a linearspring 800, as depicted in FIG. 4C, a suitable flapper valve 700 isdepicted in FIG. 5E. In this embodiment, the sealing surface 730 alsocomprises a reinforced circular portion 745 (similar to the reinforcedcircular portion 740 located on the opposing surface) that provides astiffened localized area to attach one end 820 of the linear spring 800to apply the closing force to the flapper valve 700. The reinforcedcircular portion 745 is not necessary to the present invention, but canprovide enhanced performance for the reason just stated.

The flapper valve 700 is preferably made of an elastomeric material,such as Viton, to prevent leakage around the periphery 750 of theflapper valve 700, prevent seepage through the flapper valve 700, and tominimize the effects of thermal expansion. However, the flapper valve700 can also be made of any suitable similar material or even metal. Thethickness of the flapper valve 700 need only be sufficient to provideadequate structural stability during operation. It will be wellunderstood that the addition of either (or both) of the reinforcedcircular portions 740 or 745 will provide additional stiffness andstability, which will enhance the performance of the flapper valve 700.

An embodiment of the flapper valve 700 contains a tab 770 located at itstop, the tab 770 comprising an aperture 760 centered along itslongitudinal axis to accept a hinge pin 900 (described below) and beingconfigured for adaptation into a groove or cutout section 850 located atthe inner wall 780 of the spout 340 (FIG. 4B). The tab 770 is pivotablyattached to the groove 850, for example by means of the hinge pin 900that can be inserted into the aperture 760 and that extends along anaxis parallel to the inner 730 and outer 740 faces of the flapper valve700. The tab 770 thus provides a convenient way to secure the flappervalve 700 to the inner wall 780 of the spout 340. When the hinge pin 900is secured to the inner wall 780 of the spout 340 (as described below),the flapper valve 700 is free to rotate within the spout 340 about thelongitudinal axis of the hinge pin 900 as described above.

Hinge Pin

An embodiment of the hinge pin 900 of the check valve insert (shownschematically in FIGS. 5A and 6A, and in the assembled configuration inFIG. 4B; also shown in FIG. 4C) is a conventional cylindrically-shapedpin member sized such that its diameter allows it to be inserted intothe aperture 760 of the tab 770 on the flapper valve 700 with sufficientclearance for the flapper valve 700 to freely rotate within the spout340 about the longitudinal axis of the aperture 760. Preferably thehinge pin 900 can be fixedly attached to an inner wall 780 of the spout340 to provide a secure rotational attachment for the flapper valve 700within the spout 340. Thus, in an embodiment where the closing membercomprises a rotational spring member 800 configured to provide a closingforce to an outer (downstream) face 740 of the flapper valve (see FIG.4B), the hinge pin 900 and spring member 800 are combined with theflapper valve 700 to function as a spring-loaded pivoting flap.Similarly, in an embodiment where the closing member comprises a linearspring member 800 configured to provide a closing force to an inner(upstream) face of the flap member 700 (see FIG. 4C), the tab 770 on theflapper valve 700 is configured to rotate about the hinge pin 900, andthe closing force is provided by the linear spring member 800.

Other means of securing the flapper valve 700 within the spout 340 arecertainly possible, and the embodiments shown here should not beconsidered limiting to the scope of the present invention.

Spring

An embodiment of the closing member 800 is depicted as a rotationalspring element for adaptation into the check valve insert (FIGS. 4B, 6A,6B, 6C). As shown here, this embodiment of the spring 800 consists of au-shaped wound wire material, such as that formed around a circularmandrel (not shown) to provide a circular portion 810 that is sized tofit onto the hinge pin 900, and opposing ends 820 and 830. In its“normal” position, the spring is configured as shown in FIG. 6B suchthat the flapper valve remains in the closed position due to the forceof the spring 800 against the optional reinforced circular portion 740.That is, the spring 800 and flapper valve 700 configuration arepredisposed such that the flapper valve 700 is pressed against thegraduated section 720 of the spout 340 by the spring force to preventthe flow of fuel F when the nozzle 100 is not activated (i.e., there isno fuel flowing and consequently no pressure build up to force open theflapper valve). When the user presses the lever 200 to open the mainvalve 160, the flapper valve 700 is activated (opened) by the pressurecreated by the flow of fuel F from the pump as described above. This isrepresented by the dashed lines in FIGS. 6B and 6C. When the flow offuel F stops (i.e., the user releases the lever 200 or the automaticshut off means 400 is activated as described above), the flapper valve700 closes due to the spring force 800 since the resistant pressure inthe spout 340 is not enough to maintain the flapper valve 700 in theopen position. Consequently, remaining fuel F in the nozzle 100 isretained in the spout 340.

The opposing ends 820, 830 of the rotational spring 800 performdifferent functions. The closed end of the spring 820 is configured suchthat it substantially uniformly presses against the optional reinforcedcircular portion 740 of the flapper valve 700. This feature of theflapper valve 700 is not essential to its performance, but it providesenhanced performance, especially when the flapper valve 700 is in thenominal (closed) position because it allows for the spring force to bemore effectively transferred across the sealing face 730 of the flappervalve 700 to improve the seal at the interface with the graduatedsection 720 of the spout 340.

The open ends 830 of the rotational spring member 800 are similarlyconfigured such that the spring 800 can be inserted into the inner wall780 of the dispensing end 320 of the spout 340 by means of the cutout orgroove 850 at a bottom portion of the inner wall 780 of the spout 340,the groove 850 being sized and positioned to accept the tab 770 at thetop of the flapper valve 700 such that the flapper valve 700 can freelyrotate within the spout 340 about the axis of the hinge pin 800 (asdescribed above) as it moves from its nominal (closed) position to itsopen position. Positioning the tab 770 so that it is partially locatedwithin the inner wall 780 (in the groove 850) raises the axis aboutwhich the flapper valve 700 rotates within the spout 340. This providesadditional clearance for the flapper valve 700 to rotate within thespout 340 when the nozzle 100 is operational and thereby minimizes theeffects of the check valve on the flow rate. The width of the spring 800(the lateral distance between the two single pieces of wire 820 at theopen end of the spring) is sized to securely fit into the groove 850 tominimize the lateral motion of the flapper valve 700 within the spout340. The configuration just described is suited for an embodiment wherethe closing member comprises a rotational spring 800. However, othermeans for closing the flapper valve 700 are possible; for example, theclosing member 800 could comprise a linear spring 800 (described below),or it could incorporate a piston or actuator of some sort.

In an embodiment where the closing member comprises a linear spring 800,an alternate configuration may be employed to secure the spring 800inside the spout 340. For example, one end 830 of the spring member 800can be fixedly attached to a shaft or rod 950 secured inside the spout340 as depicted in FIG. 4C, while an opposing end 820 of the springmember 800 can be rotatably attached to the optional reinforced circularportion 745 on an inner face flapper valve 700. This allows the linearspring 800 to apply a closing force to the flapper valve 700 when it isdesired to shut off the flow of liquid through the spout 340. Asdepicted in FIG. 4C, one way to fixedly attach the end 820 of the springmember 800 within the spout 340 is to employ a spacer member 970, whichcan be inserted between the shaft 950 and the stop member 720 tomaintain tension on the spring member 800. It will be understood thatthe shaft 950 can be secured within the spout 340 in other ways, thusthe configuration depicted in FIG. 4C should not be considered limitingto the scope of this embodiment of the invention. Also, with such anembodiment, it is not necessary to employ the cutout or groove 850 inthe inner wall 780 of the spout 340 (depicted in FIG. 4B) since thecombination of the tab 770 and hinge pin 900 need not accommodate therotational spring member 800 and thus take up less space inside thespout 340. Instead, the stepped down area (stop member) 720 can alsoinclude a groove or recessed area (depicted as 870 in FIG. 4C) to acceptthe tab 770 on the flapper valve 700 and to provide a convenientlocation for the axis of rotation of the flapper valve 700. This alsohas the desirable benefit of simplifying the manufacturing process forthe check valve insert. Further, it will be understood that the linearspring 800 and the shaft or rod 950 used in this embodiment are suitablysized to provide adequate stiffness and stability to ensure performanceof the flapper valve 700, but without an adverse effect on the flow ratethrough the spout 340. The configurations just described are onlyexamples of how a spring-loaded flap can be used to accomplishobjectives of the invention. Thus, the embodiments shown here should notbe considered limiting to the scope of the present invention.

The check valve insert of the present invention is positionable inproximity to the outlet end 320 of the nozzle 100, below the ventopening 350, so it does not interfere with the automatic shut-off means400 (venturi system) to automatically shut off the main valve 160 whenthe tank or container is full of fuel.

Manufacturing Considerations

The embodiments of the fuel leak prevention system 1000 and check valveinsert of the present invention are preferably incorporated into thestandard spout 340 for a fuel dispensing nozzle 100 in a manner wellunderstood, for example, by means of a dye cut during manufacturing ofthe nozzle components. In particular, the spout 340 of the nozzle 100 asdescribed here can be manufactured to incorporate the groove 850 and thegraduated section 720 to accept the spring-loaded pivoting flap thatcomprises the hinge pin 800, the flapper valve 700, and the closingmember 800 (whether rotational spring 800 or a linear spring 800 or someother device for applying a closing force to the flapper valve 700). Inthis manner, a nozzle 100 can be manufactured to incorporate anembodiment of the check valve of the present invention without the needto retrofit or replace any section of the nozzle 100. On the other hand,if desired, the filling station owner can replace the entirety of thenozzle 100 by, for example, breaking the connection 145 between the hose140 (as schematically depicted in FIGS. 1, 2A, 2B) and the inlet port130 of the body 120 and then inserting a new nozzle 100 thatincorporates an embodiment of the check valve insert as described here.

Fuel Leak Prevention System, Second Exemplary Embodiment

In another exemplary embodiment of the fuel leak prevention system 1000of the present invention, the nozzle 100 is also conventional andoperates as described thus far. However, to allow existing nozzles to beretrofitted or refurbished, without replacement, the check valve insertcan be a tabular insert or it can be press fit into the end 320 of thespout 340. Also, a removable spout extension 980 that is not provided tothe nozzle 100 during manufacturing can be added to an existing nozzle100 as described below. The spout extension 980 would preferably have across-section and external dimensions similar to that of the existingspout 340 so that the outer end 985 of the spout extension 980 can beeasily inserted into a fill pipe of a fuel tank or storage container.

In this embodiment, the check valve insert of the present invention canbe inserted into the outer end 985 of the spout extension 980 in amanner similar to that described above, and then the spout extension 980can be attached at its opposing end 975 to the outer end 320 of thespout 340 using conventional mechanical attachment that can provide asecure seal to prevent seeping of fuel F at the attachment point,including threaded means (e.g., like the silencer on a handgun), solventresistant epoxy, set screws, compression fittings, self-cutting teeth,or the like. For example, this is depicted in FIG. 7 wherein the outerend 320 of the spout 340 of an existing nozzle 100 is depicted as havingexternal screw threads 965 such that the spout extension 980, which inthis example would have internal screw treads (not shown), can mate withthe outer end 320 of the spout 340. In this embodiment, the spoutextension 980 is generally cylindrically shaped, much like the shape ofthe spout 340 itself, and it is adapted for attachment to the outer end320 of the spout 340 in such a manner so as to avoid interruption of theautomatic shut off means 400 (i.e., by not covering the vent opening350). All other functions of the components of the check valve insert,namely, the flapper valve 700, the closing member (spring) 800, thehinge pin 900, and the stop member 720, and their operation within thespout extension 980 remain the same as described above in connectionwith the first embodiment of the present invention.

Numerous characteristics and advantages have been set forth in theforegoing description, together with details of structure and function.While the invention has been disclosed in several forms, it will beapparent to those skilled in the art that many modifications, additions,and deletions, especially in matters of shape, size, and arrangement ofparts, can be made therein without departing from the spirit and scopeof the invention and its equivalents as set forth in the followingclaims. Therefore, other modifications or embodiments as may besuggested by the teachings herein are particularly reserved as they fallwithin the breadth and scope of the claims here appended.

What is claimed is:
 1. A leak prevention system for use with a liquiddispensing nozzle, the nozzle in fluid communication with a liquiddispensing pump, the system comprising: a body portion; a spout assemblyextending from the body portion, the spout assembly having an outlet endconfigured for dispensing the liquid; a flow control valve in the bodyportion operable to allow or prevent the flow of liquid through a flowpassage defined by the body portion; a hinge pin fixedly attached to aninner wall of the outlet end of the spout assembly; a shaft fixedlyattached to the inner wall of the outlet end of the spout assemblyupstream of the hinge pin; and a check valve comprising: a flap memberpivotably attached within the spout assembly; and a closing membermounted within the spout assembly and oriented to engage the flap memberto apply a closing force to a seating surface of the flap member insidethe spout assembly; the check valve positioned within the spout assemblyand downstream of the flow control valve and being responsive to theflow of liquid through the body portion and into the spout assembly; andwherein the check valve is biasedly disposed to remain closed when noliquid is flowing through the nozzle so as to retard liquid fromdripping from the outlet end of the spout assembly when the nozzle isnot activated, and wherein one end of the closing member is attached tothe shaft and an opposing end of the closing member is attached to theseating surface of the flap member such that the closing member is inconstant communication with at least a portion of the seating surface ofthe flap member.
 2. The system of claim 1, wherein the check valve islocated in proximity to the outlet end of the spout assembly.
 3. Thesystem of claim 1, wherein the check valve further comprises: a stopmember positioned inside the spout assembly and adapted to provide aseating area for the seating surface of the flap member and forpreventing the flap member from rotating beyond a preset orientation;wherein the closing force applied by the closing member is large enoughto cause the seating surface of the flap member to remain seated whenthe nozzle is not activated, but the closing force is not so large toprevent the flap member from rotating to substantially open the spoutassembly and allow the flow of liquid when the nozzle is activated. 4.The system of claim 1, wherein the closing member is a spring.
 5. Thesystem of claim 1, wherein the flap member further comprises a tablocated in proximity to an outer edge of the flap member, the tab havinga bore through a longitudinal axis of the tab and configured to receivethe hinge pin such that the flap member can rotate about thelongitudinal axis.
 6. The system of claim 5, wherein the stop membercontains a groove adapted to receive at least a portion of the tab toallow the flap member to rotate within the spout assembly and fully seatagainst the stop member with minimal interference from the inner wall.7. The system of claim 1, wherein at least a portion of the seatingsurface of the flap member is constructed of an elastomeric material;and wherein the seating surface of the flap member further comprises areinforced portion substantially centrally located and configured toreceive the closing member so as to distribute the closing member forceacross the flap member.
 8. A leak prevention system for use with aliquid dispensing nozzle, the nozzle being in fluid communication with aliquid dispensing pump and including a body portion, a spout assemblyextending from the body portion, the spout assembly having an outlet endconfigured for dispensing the liquid, and a flow control valve in thebody portion operable to allow or prevent the flow of liquid through aflow passage defined by the body portion, the system comprising: a spoutextension configured to be fixedly attached to the outlet end of thespout assembly and having an outlet end configured for dispensing theliquid; a hinge pin fixedly attached to an inner wall of the outlet endof the spout extension; a shaft fixedly attached to the inner wall ofthe outlet end of the spout extension upstream of the hinge pin; and acheck valve comprising: a flap member pivotably attached within thespout extension; and a closing member mounted within the spout extensionand oriented to engage the flap member to apply a closing force to aseating surface of the flap member inside the spout extension; the checkvalve positioned within the spout extension and downstream of the flowcontrol valve and being responsive to the flow of liquid through thebody portion and into the spout assembly and the spout extension;wherein the check valve is biasedly disposed to remain closed when noliquid is flowing through the nozzle so as to retard liquid fromdripping from the outlet end of the spout extension when the nozzle isnot activated; and wherein one end of the closing member is attached tothe shaft and an opposing end of the closing member is attached to theseating surface of the flap member such that the closing member is inconstant communication with at least a portion of the seating surface ofthe flap member.
 9. The system of claim 8, wherein the check valve islocated in proximity to the outlet end of the spout extension.
 10. Thesystem of claim 9, wherein the check valve further comprises: a stopmember positioned inside the spout extension and adapted to provide aseating area for the seating surface of the flap member and forpreventing the flap member from rotating beyond a preset orientation;wherein the closing force applied by the closing member is large enoughto cause the seating surface of the flap member to remain seated whenthe nozzle is not activated, but the closing force is not so large toprevent the flap member from rotating to substantially open the spoutextension and allow the flow of liquid when the nozzle is activated. 11.The system of claim 10, wherein the closing member is a spring.
 12. Thesystem of claim 11, wherein the flap member further comprises a tablocated in proximity to an outer edge of the flap member, the tab havinga bore through a longitudinal axis of the tab and configured to receivethe hinge pin such that the flap member can rotate about thelongitudinal axis.
 13. The system of claim 11, wherein the stop membercontains a groove adapted to receive at least a portion of the tab toallow the flap member to rotate within the spout extension and fullyseat against the stop member with minimal interference from the innerwall.
 14. The system of claim 8, wherein at least a portion of theseating surface of the flap member is constructed of an elastomericmaterial; and wherein the seating surface of the flap member furthercomprises a reinforced portion substantially centrally located andconfigured to receive the closing member so as to distribute the closingmember force across the flap member.
 15. A leak prevention system foruse with a liquid dispensing nozzle, the nozzle in fluid communicationwith a liquid dispensing pump, the system comprising: a body portion; aspout assembly extending from the body portion, the spout assemblyhaving an outlet end configured for dispensing the liquid; a flowcontrol valve in the body portion operable to allow or prevent the flowof liquid through a flow passage defined by the body portion; a hingepin fixedly attached to an inner wall of the outlet end of the spoutassembly; a shaft fixedly attached to the inner wall of the outlet endof the spout assembly upstream of the hinge pin; and a check valvecomprising: a flap member pivotably attached within the spout assembly,the flap member comprising a tab located in proximity to an outer edgeof the flap member, the tab having a bore through a longitudinal axis ofthe tab and configured to receive the hinge pin such that the flapmember can rotate about the longitudinal axis; and a spring mountedwithin the spout assembly and oriented to engage the flap member toapply a closing force to a seating surface of the flap member inside thespout assembly, wherein one end of the spring is attached to the shaftand an opposing end of the spring is attached to the seating surface ofthe flap member such that the spring is in constant communication withat least a portion of the seating surface of the flap member; a stopmember positioned inside the spout assembly and adapted to provide aseating area for the seating surface of the flap member and forpreventing the flap member from rotating beyond a preset orientation,wherein the stop member contains a groove adapted to receive at least aportion of the tab to allow the flap member to rotate within the spoutassembly and fully seat against the stop member with minimalinterference from the inner wall; wherein the closing force applied bythe spring is large enough to cause the seating surface of the flapmember to remain seated when the nozzle is not activated, but theclosing force is not so large to prevent the flap member from rotatingto substantially open the spout assembly and allow the flow of liquidwhen the nozzle is activated; the check valve positioned within thespout assembly and downstream of the flow control valve and beingresponsive to the flow of liquid through the body portion and into thespout assembly; and wherein the check valve is biasedly disposed toremain closed when no liquid is flowing through the nozzle so as toretard liquid from dripping from the outlet end of the spout assemblywhen the nozzle is not activated.
 16. The system of claim 15, wherein atleast a portion of the seating surface of the flap member is constructedof an elastomeric material.
 17. The system of claim 15, wherein theseating surface of the flap member further comprises a reinforcedportion substantially centrally located and configured to receive theclosing member so as to distribute the closing member force across theflap member.